REPLACEMENT GEARBOXES and GEARS available from Loco Doc
GEARBOXES FOR 3MM AXLES (USED ON ALMOST ALL HO BRASS)
| BRAND | PSC | PSC | PSC | PSC | NWSL | NWSL | NWSL | NWSL | NWSL | NWSL | NWSL | NWSL |
| PART # |  4018 |  4018.1 | 4018.13 | 4018.12 | 140-6 | 139-6 | 136-6 | 151-6 | 150-6 | 241-6 | 240-6 | 170-6 |
| RATIO | 27/1 | 36/1 | 27/1 | 27/1 | 27/1 | 27/1 | 27/1 | 36/1 | 36/1 | 28/1 | 28/1 | 50/1 |
| #OF IDLERS | 1 | 1 | 0 | 1 | 0 | 1 | 2 | 0 | 1 | 0 | 1 | 1 |
| WORM OFFSET | .775" | .860" | .310" | .710" | .256" | .591" | .925" | .303" | .732" | .323" | .78" | .365" |
| CASE | METAL | MET | PLAST | PLAS | PLAS | PLAS | PLAS | PLAS | PLAS | PLAS | PLAS | PLAS |
| Min.Driver" | 49-40" | 62-54" | 40-30" | 40-30" | 46-33" | 46-33" | 40-33" | 56-40" | 56-40" | 58-43" | 58-43" | 33-28" |
| OPTIONS | A,C | B | W | N,X | Q,W | P,W | P,X | Q,W | Q,X | Z | ||
| PRICE | $38.50 | $17.25 | $12.25 | $16.50 | $24.95 | $29.95 | $31.95 | $24.95 | $29.95 | $24.95 | $29.95 | $34.95 |
POLISHED STEEL WORMS TO REPLACE WORN AND DEFECTIVE GEARS
 
The worm is the most easily damaged gear and will destroy the gear it drives
if it has a rough tooth surface or if it is damaged. The worm MUST be made of
a discimilar and harder material than the gear it drives. Poor quality, worn
or soft brass worms should be replaced before they damage other gears.
I always replace any brass worm with a NWSL polished steel
worm. It is a very cheap investment in longer gear life. A Standard worm has threads running like a
screw or bolt and runs foreward turning clockwise. A reverse worm is opposite.
REPLACEMENT STEEL WORMS
| DESCRIPTION | NWSL | NWSL | NWSL | NWSL | NWSL | NWSL |
| GEAR PITCH | 3MOD | 3MOD | 72DP-3.5MOD | 72DP-3.5MOD | 4MOD | 4MOD |
| GEAR CUT | STD.WORM | REV.WORM | STD.WORM | REV.WORM | STD.WORM | REV.WORM |
| GEAR O.D. | 5MM | 5MM | 4.8MM | 4.8MM | 6MM | 6MM |
| 1.2MM SHAFT | 10800-6x + | 10801-6 + | 50800-6 + | |||
| 1.5MM SHAFT | 1313-6 ^ | 1335-6 ^ | 10400-6 x | 10401-6 x | ||
| 2.OMM SHAFT | 1312-6 ^ | 1334-6 ^ | 10500-6 x | 10501-6 x | 50500-6 + | |
| 2.4MM SHAFT | 230600-6 - | 230601-6 ^ | 10000-6 0 | 10001-6 x | 50600-6 - | 50601-6 - |
LOCODOC DELRIN IDLER GEAR UPGRADES FOR HOn3 WESTSIDE LOCOMOTIVES
 
Quite a few very good HOn3 locomotives built
by Nakamura were produced with a brass worm driving brass idler gears
rotating on 3mm brass shafts. A rule of gear design is that the worm
must be made of a harder and discimilar material than the "worm gear"
it drives and the pivot shaft must be a smooth and harder material than
any gear rotating on it. Many locomotives ( Lambert C&S 2-6-0 , Westside C-25,
K-37, compound K-27, original slide valve K-27 and possibly others ) should
have their brass idler gears replaced with delrin gears.
If the shaft is worn or if you want a quieter, smoother
and lower friction drive that also increases flywheel coast, LocoDoc has developed a
custom NWSL made 26 tooth delrin idler gear mounted on a 1.5mm hardened steel shaft
for greater stability. It also includes two custom brass bearings to fit the shaft
and center the gear in the gearbox. This is a big improvement over the NWSL 305-6
gear that loosly mounts on the original large 3mm. brass pivot shaft.
LocoDoc #305 delrin idler gear upgrade
( PHOTO )
$20
LOCODOC DELRIN IDLER GEARS FOR KEY MODELS
Several models built by Samhongsa had brass idler gears which tend to be noisy and wear out
and several rotate on brass sholdered screws, a short lived design. The following delrin idler
gears are custom made by us using NWSL gear stock.
LocoDoc C&S #22 2-6-0 ( PHOTO )
$20
LocoDoc C&S #58 2-8-0 (also #60, #65 & #69)
( PHOTO )
$20
LocoDoc RGS #42 2-8-0 This is a corrected
(sleaved down)NWSL #2177
  $20
LocoDoc C&S #71 2-8-0 This
is a corrected NWSL #2177 (bored out)
  $20
NWSL DELRIN IDLER GEARS TO UPGRADE HOn3 LOCOMOTIVES
NWSL #305-6 to replace brass idler gears in
Nakamura made HOn3 locos
$6.95
NWSL #2146 FOR WS & Balboa(2nd run) D&RGW
T-12 originly made for me
$11.95
NWSL #2154 FOR WS WSLC #3 steel worm to replace soft brass one
$9.95
NWSL #2161 FOR WS NCNG #9 but not SP#18 (with idler gear)
Some have undersize hole $9.95
NWSL #2177 FOR Key C*S #71 and RGS #42 requires shimming the pivot hole
$9.95
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